In related art, a system that projects a plurality of images on a screen by using a plurality of projectors is known. For example, a system that projects a plurality of parallax images to display a 3D image, a system that projects the same image in a superimposed manner to increase luminance, and the like are known. Further, a system that displays a plurality of images in a partially overlapped manner, thereby achieving image displaying on a large screen is also known.
For example, Patent Document 1 describes a multi-projection system that combines a plurality of projection images projected from a plurality of projectors to form an entire image and displays a high-resolution, large-screen image. Disclosed is a technology that intends to reduce an influence of distortion of the projection image due to the shape of a projection lens or the like in this system. Specifically, an area, a distortion amount of which in the projection image projected from each projector is equal to or less than a predetermined threshold value is detected. Then, images of the area are overlapped, and thus an entire image is formed (paragraph [0019], FIG. 3, and the like in Patent Document 1).
Patent Document 1: Japanese Patent Application Laid-open No. 2009-130569